Using machine learning algorithms to enhance IoT system security

The term “Internet of Things” (IoT) refers to a system of networked computing devices that may work and communicate with one another without direct human intervention. It is one of the most exciting areas of computing nowadays, with its applications in multiple sectors like cities, homes, wearable equipment, critical infrastructure, hospitals, and transportation. The security issues surrounding IoT devices increase as they expand. To address these issues, this study presents a novel model for enhancing the security of IoT systems using machine learning (ML) classifiers. The proposed approach analyzes recent technologies, security, intelligent solutions, and vulnerabilities in ML IoT-based intelligent systems as an essential technology to improve IoT security. The study illustrates the benefits and limitations of applying ML in an IoT environment and provides a security model based on ML that manages autonomously the rising number of security issues related to the IoT domain. The paper proposes an ML-based security model that autonomously handles the growing number of security issues associated with the IoT domain. This research made a significant contribution by developing a cyberattack detection solution for IoT devices using ML. The study used seven ML algorithms to identify the most accurate classifiers for their AI-based reaction agent’s implementation phase, which can identify attack activities and patterns in networks connected to the IoT. The study used seven ML algorithms to identify the most accurate classifiers for their AI-based reaction agent’s implementation phase, which can identify attack activities and patterns in networks connected to the IoT. Compared to previous research, the proposed approach achieved a 99.9% accuracy, a 99.8% detection average, a 99.9 F1 score, and a perfect AUC score of 1. The study highlights that the proposed approach outperforms earlier machine learning-based models in terms of both execution speed and accuracy. The study illustrates that the suggested approach outperforms previous machine learning-based models in both execution time and accuracy.

• Anomaly detection ML algorithms can learn IoT device behavior and network interactions through anomaly detection.ML models can detect unusual IoT activity using real-time data.This helps detect security breaches like unauthorized access or malicious acts and prompt appropriate responses.• Threat intelligence and prediction ML can analyze big security data sets and provide insights.ML models may discover new risks, anticipate attack pathways, and give actionable insight to IoT security practitioners by analyzing data from security feeds, vulnerability databases, and public forums.• Firmware and software vulnerability analysis Researchers may use ML to analyze IoT firmware and software for vulnerabilities.ML models may discover IoT device firmware and software security problems by training on known vulnerabilities and coding patterns.This helps manufacturers repair vulnerabilities before deployment or deliver security patches quickly.• Behavior-based authentication ML algorithms can learn IoT devices and user behavior.By analyzing device usage patterns, ML models may create predictable behavior profiles.ML can require extra authentication or warn for illegal access when a device or user deviates considerably from the learned profile.• Data privacy and encryption ML can assist in ensuring data privacy and security in IoT systems.ML algo- rithms may provide homomorphic encryption, which permits calculations on encrypted data.ML can perform data anonymization and de-identification to safeguard sensitive data and facilitate analysis and insights.
In general, ML techniques must be used in conjunction with other security measures to offer complete security for IoT systems.ML algorithms and methods have been applied in various tasks, including machine translation, regression, clustering, transcription, detection, classification, probability mass function, sampling, and estimation of probability density.Numerous applications utilize ML techniques and algorithms, such as spam identification, image and video recognition, customer segmentation, sentiment analysis, demand forecasting, virtual personal assistants, detection of fraudulent transactions, automation of customer service, authentication, malware detection, and speech recognition 4 .
In addition, IoT and ML integration can enhance the devices of IoT levels of security, thereby increasing their reliability and accessibility.ML's advanced data exploration methods play an important role in elevating IoT security from only providing security for communication devices to intelligent systems with a high level of security 5 .
ML-based models have emerged as a response to cyberattacks within the IoT ecosystem, and the combination of Deep Learning (DL) and ML approaches represents a novel and significant development that requires careful consideration.Numerous uses, including wearable smart gadgets, smart homes, healthcare, and Vehicular Area Networks (VANET), necessitate the implementation of robust security measures to safeguard user privacy and personal information.The successful utilization of IoT is evident across multiple sectors of modern life 6 .By 2025, we expect that the IoT will have an economic effect of $2.70-$6.20 trillion.Research findings indicate that ML and DL techniques are key drivers of automation in knowledge work, thereby contributing to the economic impact.There have been many recent technological advancements that are shaping our world in significant ways.By 2025, we expect an estimated $5.2-$6.7 trillion in annual economic effects from knowledge labor automation 7 .
This research study addresses the vulnerabilities in IoT systems by presenting a novel ML-based security model.The proposed approach aims to address the increasing security concerns associated with the Internet of Things.The study analyzes recent technologies, security, intelligent solutions, and vulnerabilities in IoT-based smart systems that utilize ML as a crucial technology to enhance IoT security.The paper provides a detailed analysis of using ML technologies to improve IoT systems' security and highlights the benefits and limitations of applying ML in an IoT environment.When compared to current ML-based models, the proposed approach outperforms them in both accuracy and execution time, making it an ideal option for improving the security of IoT systems.The creation of a novel ML-based security model, which can enhance the effectiveness of cybersecurity systems and IoT infrastructure, is the contribution of the study.The proposed model can keep threat knowledge databases up to date, analyze network traffic, and protect IoT systems from newly detected attacks by drawing on prior knowledge of cyber threats.
The study comprises five sections: "Related works" section presents a summary of some previous research."IoT, security, and ML" section introduces the Internet of Things' security and ML aspects."The proposed IoT framework architecture" section presents the proposed IoT framework architecture, providing detailed information and focusing on its performance evaluation."Result evaluation and discussion" section provides an evaluation of the outcomes and compares them with other similar systems.We achieve this by utilizing appropriate datasets, methodologies, and classifiers."Conclusions and upcoming work" section concludes the discussion and outlines future research directions.

Related works
The idea of security in IoT devices has been recently articulated in studies that analyze the security needs at several layers of architecture, such as the application, cloud, network, data, and physical layers.Layers have examined potential vulnerabilities and attacks against IoT devices, classified IoT attacks, and explained layer-based security requirements 8 .On the other hand, industrial IoT (IIoT) networks are vulnerable to cyberattacks.Developing IDS is important to secure IIoT networks.The authors presented three DL models, LSTM, CNN, and a hybrid, to identify IIoT network breaches 9 .The researchers used the UNSW-NB15 and X-IIoTID datasets to identify normal and abnormal data, then compared them to other research using multi-class, and binary classification.The hybrid LSTM + CNN model has the greatest intrusion detection accuracy in both datasets.The researchers also assessed the implemented models' accuracy in detecting attack types in the datasets 9 .
In Ref. 10 , the authors introduced the hybrid synchronous-asynchronous privacy-preserving federated technique.The federated paradigm eliminates FL-enabled NG-IoT setup issues and protects all its pieces with Two-Trapdoor Homomorphic Encryption.The server protocol blocks irregular users.The asynchronous hybrid LEGATO algorithm reduces user dropout.By sharing data, they assist data-poor consumers.In the presented model, security analysis ensures federated correctness, auditing, and PP.Their performance evaluation showed higher functionality, accuracy, and reduced system overheads than peer efforts.For medical devices, the authors of Ref. 11 developed an auditable privacy-preserving federated learning (AP2FL) method.By utilizing Trusted Execution Environments (TEEs), AP2FL reduces issues about data leakage during training and aggregation activities on both servers and clients.The authors of this study aggregated user updates and found data similarities for non-IID data using Active Personalized Federated Learning (ActPerFL) and Batch Normalization (BN).
In Ref. 12 , the authors addressed two major consumer IoT threat detection issues.First, the authors addressed FL's unfixed issue: stringent client validation.They solved this using quantum-centric registration and authentication, ensuring strict client validation in FL.FL client model weight protection is the second problem.They suggested adding additive homomorphic encryption to their model to protect FL participants' privacy without sacrificing computational speed.This technique obtained an average accuracy of 94.93% on the N-baIoT dataset and 91.93% on the Edge-IIoTset dataset, demonstrating consistent and resilient performance across varied client settings.
Utilizing a semi-deep learning approach, SteelEye was created in Ref. 13 to precisely detect and assign responsibility for cyberattacks that occur at the application layer in industrial control systems.The proposed model uses category boosting and a diverse range of variables to provide precise cyber-attack detection and attack attribution.SteelEye demonstrated superior performance in terms of accuracy, precision, recall, and Fl-score compared to state-of-the-art cyber-attack detection and attribution systems.
In Ref. 14 , researchers developed a fuzzy DL model, an enhanced adaptive neuro-fuzzy inference system (ANFIS), fuzzy matching (FM), and a fuzzy control system to detect network risks.Our fuzzy DL finds robust nonlinear aggregation using the fuzzy Choquet integral.Metaheuristics optimized ANFIS attack detection's error function.FM verifies transactions to detect blockchain fraud and boost efficiency.The first safe, intelligent fuzzy blockchain architecture, which evaluates IoT security threats and uncertainties, enables blockchain layer decision-making and transaction approval.Tests show that the blockchain layer's throughput and latency can reveal threats to blockchain and IoT.Recall, accuracy, precision, and F1-score are important for the intelligent fuzzy layer.In blockchain-based IoT networks, the FCS model for threat detection was also shown to be reliable.
In Ref. 15 , the study examined Federated Learning (FL) privacy measurement to determine its efficacy in securing sensitive data during AI and ML model training.While FL promises to safeguard privacy during model training, its proper implementation is crucial.Evaluation of FL privacy measurement metrics and methodologies can identify gaps in existing systems and suggest novel privacy enhancement strategies.Thus, FL needs full research on "privacy measurement and metrics" to thrive.The survey critically assessed FL privacy measurement found research gaps, and suggested further study.The research also included a case study that assessed privacy methods in an FL situation.The research concluded with a plan to improve FL privacy via quantum computing and trusted execution environments.

IoT attacks and security vulnerabilities
Critical obstacles standing in the way of future attempts to see IoT fully accepted in society are security flaws and vulnerabilities.Everyday IoT operations are successfully managed by security concerns.In contrast, they have a centralized structure that results in several vulnerable points that may be attacked.For example, unpatched vulnerabilities in IoT devices are a security concern due to outdated software and manual updates.Weak authentication in IoT devices is a significant issue due to easy-to-identify passwords.Attackers commonly target vulnerable Application Programming Interfaces (APIs) in IoT devices using code injections, a man-in-the-middle (MiTM), and Distributed Denial-of-Service (DDoS) 16 .Unpatched IoT devices pose risks to users, including data theft and physical harm.IoT devices store sensitive data, making them vulnerable to theft.In the medical field, weak security in devices such as heart monitors and pacemakers can impede medical treatment.Figure 1 illustrates the types of IoT attacks (threats) 17 .Unsecured IoT devices can be taken over and used in botnets, leading to cyberattacks such as DDoS, spam, and phishing.The Mirai software in 2016 encouraged criminals to develop extensive botnets for IoT devices, leading to unprecedented attacks.Malware can easily exploit weak security safeguards in IoT devices 18 .Because there are so many connected devices, it may be difficult to ensure IoT device security.Users must follow fundamental security practices, such as changing default passwords and prohibiting unauthorized remote access 19 .Manufacturers and vendors must invest in securing IoT tool managers by proactively notifying users about outdated software, enforcing strong password management, disabling remote access for unnecessary functions, establishing strict API access control, and protecting command-and-control (C&C) servers from attacks.

IoT applications' support security issues
Security is a major requirement for almost all IoT applications.IoT applications are expanding quickly and have impacted current industries.Even though operators supported some applications with the current technologies of networks, others required greater security support from the IoT-based technologies they use 20 .The IoT has several uses, including home automation and smart buildings and cities.Security measures can enhance home security, but unauthorized users may damage the owner's property.Smart applications can threaten people's privacy, even if they are meant to raise their standard of living.Governments are encouraging the creation of intelligent cities, but the safety of citizens' personal information may be at risk 21,22 .
Retail extensively uses the IoT to improve warehouse restocking and create smart shopping applications.Augmented reality applications enable offline retailers to try online shopping.However, security issues have plagued IoT apps implemented by retail businesses, leading to financial losses for both clients and companies.

IoT security attacks based on each layer
IoT devices' architecture includes five layers: perception, network Layer, middleware (information processing), application, and business (system management).Figure 2 illustrates how the development of IoT ecosystems has changed from a three-layer to a five-layer approach.IoT threats can be physical or cyber, with cyberattacks being passive or active.IoT devices can be physically damaged by attacks, and various IoT security attacks based on each tier are described 26 .Perception layer attacks are intrusions on IoT physical components, for example, devices and sensors.Some of the typical perception layer attacks are as follows: 1. Botnets Devices get infected by malware called botnets, like Mirai.The bot's main objectives are to infect improperly configured devices and assault a target server when given the order by a botmaster 27 .2. Sleep deprivation attack Attacks from sleep deprivation are linked to battery-powered sensor nodes and equipment.Keeping the machines and devices awake for a long time is the aim of the sleep disturbances assault 28 .3. Node tampering and jamming Node tampering attacks are launched by querying the machines to acquire accessibility to and change confidential data, like routing data tables and cryptographic shared keys.A node jamming assault, on the other hand, occurs when perpetrators breach the radio frequencies of wireless sensor nodes 29 .4. Eavesdropping By allowing the attacker to hear the information being transferred across a private channel, eavesdropping is an exploit that puts the secrecy of a message in danger 30 .
These attacks can harm most or all IoT system physical components and can be prevented by implementing appropriate security measures.
Network layer attacks aim to interfere with the IoT space's network components, which include routers, bridges, and others.The following are some examples of network layer attacks: Cloud-based attacks, breaches of authentication, and signature packaging attacks are the three most common forms of middleware attacks.
These attacks can be prevented by implementing appropriate security measures.Smart cities, smart grids, and smart homes are some examples of apps included in the application layer.An application layer attack relates to the security flaws in IoT apps.Here are a few examples of application layer attacks 32 : • Malware The use of executable software by attackers to interfere with network equipment is known as malware.
• Phishing attack This is a sort of breach that seeks to get users' usernames and passwords by making them appear to be reliable entities.

• Code injection attack
The main goal of an injector attack into a program or script code is to inject an execut- able code into the memory space of the breached process.
Appropriate security measures can help prevent these attacks as well.

Overview of ML within the IoT
IoT systems are susceptible to hackers because they lack clear boundaries and new devices are always being introduced.There is a possibility to create algorithms that can learn about the behavior of objects and other IoT components inside such large networks by utilizing ML and DL approaches.By using these techniques to predict a system's expected behavior based on past experiences, security protocols can be developed to a significant extent.

ML techniques and their applications in IoT
ML techniques play an essential role in analyzing and extracting insights from the massive amount of data produced by IoT devices.Here are some popular ML techniques and their applications in the IoT: 1. Supervised learning This type of algorithm learns from labeled training data.Various applications in the IoT can utilize supervised learning, such as: • Anomaly detection By training ML models to recognize abnormal patterns or behaviors in IoT sensor data, we can identify anomalies or potential security breaches.• Predictive maintenance By analyzing past sensor data, supervised learning algorithms can predict equip- ment failures or maintenance requirements.This enables the implementation of proactive maintenance measures, leading to a decrease in downtime.• Environmental monitoring ML models can learn from sensor data to predict environmental conditions like air quality, water pollution, or weather patterns.
2. Unsupervised learning Unsupervised learning algorithms extract patterns or structures from unlabeled data without predefined categories.In IoT, unsupervised learning techniques find applications such as: • Clustering ML models can group similar IoT devices or data points, facilitating resource allocation, load balancing, or identifying network segments.• Dimensionality reduction Unsupervised learning techniques like autoencoders or principal component analysis (PCA) make it easier to analyze IoT data.• Behavioral profiling Unsupervised learning can help in understanding the normal behavior of IoT devices or users, enabling the detection of deviations or anomalies.

3.
Reinforcement learning Reinforcement learning aims to maximize a reward by training an agent how to interact with its environment and use feedback to improve its performance.The following applications use reinforcement learning on the IoT.
• Energy management ML models can learn optimal energy allocation strategies for IoT devices to maxi- mize energy efficiency or minimize costs.ML for IoT security ML is a promising approach for defending IoT devices against cyberattacks.It offers a unique strategy for thwarting assaults and provides several benefits, including designing sensor-dependent systems, providing real-time evaluation, boosting security, reducing the flowing data, and utilizing the large quantity of data on the Internet for all individualized user applications.The influence of ML on the IoT's development is crucial for enhancing practical smart applications.ML has garnered scientific attention recently and is being applied to IoT security as well as the growth of numerous other industries.Effective data exploration methods for identifying "abnormal" and "normal" IoT components and behavior of devices inside the IoT ecosystem are DL and ML.Consequently, to transform the security of IoT systems from enabling secure Device-to-Device (D2D) connectivity to delivering intelligence security-based systems, ML/DL techniques are needed 33 .
Enhancing IoT security using the algorithms of ML ML approaches, such as ensemble learning, k-means clustering, Random Forest (RF), Association Rule (AR), Decision Tree (DT), AdaBoost, Support Vector Machine (SVM), XGBoost, and K-Nearest Neighbor (KNN), have benefits, drawbacks, and applications in IoT security.DT, a natural ML technique, resembles a tree, with branches and leaves that serve as nodes in the model.In classification, SVM maximizes the distance between the closest points and the hyperplane to classify the class 34 .In identifying DDoS attacks, RF performs better than SVM, ANN, and KNN.A Principal Component Analysis (PCA) with KNN and classifier softmax has been suggested in Ref. 35 to develop a system that has great time efficiency while still having cheap computation, which enables it to be employed in IoT real-time situations.

Limitations of applying ML in networks of IoT
Using ML approaches for IoT networks has limitations because of dedicated processing power and IoT machines' limited energy.IoT networks generate data with a variety of structures, forms, and meanings, and traditional ML algorithms are ill-equipped to handle these massive, continuous streams of real-time data.The semantic and syntactic variability in this data is evident, particularly in the case of huge data, and heterogeneous datasets with unique features pose problems for effective and uniform generalization.ML assumes that all the dataset's statistical attributes are constant, and the data must first go through preprocessing and cleaning before fitting into a particular model.However, in the real world, data comes from multiple nodes and has different representations with variant formatting, which presents challenges for ML algorithms 36 .The ecosystem of the IoT is given value by virtualized resources of the network, explaining its variability and quick expansion.NFV and SDN can offer advanced virtual monitoring tools like Deep Packet Inspectors (DPIs) and Intrusion Detection Systems (IDSs).They can provide scalable network security equipment, as well as deploy and configure on-demand components, such as authentication systems and firewalls, to defend against attacks that have been identified by monitoring agents.When processing for security is offloaded from resource-constrained IoT devices to virtual instances, the resulting boost in efficiency and drop in energy consumption clear the way for other useful applications to be implemented.IoT security hardware lacks NFV's flexibility and enhanced security.NFV's value-added features improved IoT security, even if they did not replace current solutions.

The proposed IoT framework architecture
• Machine learning (ML) ML is an algorithmic artificial intelligence (AI) discipline that uses techniques to give intelligence to devices and computers.ML methods include unsupervised, supervised, and reinforcement learning.They are typically used in the security of networks.ML is used to specify and precisely identify the security regulations of the data plane.In mitigating a sort of attack given by tagging traffic networks or creating policies to access control, the difficulty is to fine-tune key security protocol parameters.Moreover, several ML approaches may prevent IoT attacks.
(a) Supervised learning In algorithms of supervised learning, the model output is known even though the underlying relationships between the data are unknown.This model is often trained with two datasets: One for "testing" and "evaluating" the driven model and another to "learn" from.Within the context of security, it is common to compare a suspected attack to a database of known threats.(b) Unsupervised learning Data is not pre-labeled, and the model is unknown.It sets it apart from supervised learning.It aims to classify and find patterns in the data.(c) Reinforcement learning It looks at problems and methods to enhance its model through study.It employs trial and error and incentive mechanisms to train its models in a novel way.A metric known as the "value function" is determined by tracking the output's success and applying the reward to its formula.This value tells the model how well it is evaluated, so it may adjust its behavior accordingly.4 demonstrates the closed-loop automation phases, starting with detection and monitoring and ending with preventing threats.To ensure complete security, the system suggested integrating the enablers and countermeasures from the previous subsections.This framework enforces security policies beginning with the design and concluding with the application and maintenance.Two primary framework levels are shown in Fig. 3 (i.e., security orchestration and security enforcement layers).The two layers and their closed-loop automation intercommunications to detect and prevent attacks are discussed below.authorized IoT devices.Attacks would be primarily addressed at three levels: (1) IoT devices, via IoT controllers;

The proposed security model
(2) network, via SDN controllers; and (3) cloud, via an NFV orchestrator.By implementing VNF security and setting the interaction through SDN networking, the security framework features may be properly implemented within the IoT territory.The security enforcement plan was developed to match closely with ETSI and Open Networking Foundation (ONF) guidelines for NFV and SDN.As shown in Fig. 1, the security enforcement mechanisms consist of five separate logical blocks.
• Management and control block It analyzes the components required to manage NFV and SDN infrastruc- tures.It uses SDN controllers and ETSI MANO stack modules for this.To implement efficient security functions, the SDN controllers and NFV orchestrator must work closely together as NFV is frequently used alongside SDN to alter programmatically the network based on policies and resources.• VNF block Taking into consideration the VNFs that have been implemented across the virtualization infrastructure to implement various network-based security measures, the threat and protection measures required by the rules of security will be met with a focus on the delivery of sophisticated VNF security (e.g., IDS/IPS, virtual firewalls, etc.).• Infrastructure block It includes every hardware component needed to construct an IaaS layer, including computers, storage devices, networks, and the software used to run them in a virtualized environment.
In addition to the elements of the network that are in charge of transmitting traffic while adhering to the regulations that have been specified by the SDN controller, a set of security probes is included in this plane to gather data for use by the monitoring services.• Monitoring agents block Its primary duty is reporting network activity and IoT actions to identify and prevent various types of attacks.In the proposed model, the detection technique may make use of either network patterns or IoT misbehavior.Using SDN-enabled traffic mirroring, every bit of data that is being sent over the network can be seen.The Security Orchestration Plane hosts an AI-based response agent that receives logs from the monitoring agents describing malicious transactions.• The IoT domain block It refers to the interconnected system of cameras, sensors, appliances, and other physical objects that form the SDN.The proposed methodology considers the substantial risk these devices pose to data privacy and integrity, and it tries to enforce the security standards in this domain.

Security orchestration layer
This layer has the task of setting up real-time rules of security depending on the current state of monitoring data and adjusting the policies dynamically based on their context.It is a novel part of the proposed framework that communicates with the security enforcement layer to request the necessary actions to be taken to enforce security regulations inside the IoT domain.Virtual security enablers must be created, configured, and monitored to deal with the present attack.Figure 2 is a diagrammatic representation of the major cooperation that happens among various framework components.This study proposes a feedback automation mechanism control system consisting of an oversight agent, an AI-based reaction agent, and an orchestrator for security.The latter protects against dangers by utilizing an NFV orchestrator, SDN controller, and IoT controller (see Figs. 3, 4).
• AI-based reaction agent This part orders the security orchestrator to perform predetermined measures in response to an incident.This block, as shown in Fig. 4, makes use of the information collected by the monitoring agent from IoT domains and the network.This part employs ML models that have been trained on network topologies and the actions of IoT devices to identify potential dangers.For the security orchestrator, these ML models will be able to prescribe the optimal template for policies of security.Figure 4 also shows how to identify security threats from observations of network patterns and/or IoT activities.The security orchestrator would then be informed of the discovered danger level (where every level from L1 to L5 belongs to a different predefined security policy).As shown in Fig. 4, we developed an AI-based reaction agent that uses seven ML techniques to recognize IoT-related attack activities and/or patterns in a network.These techniques are Random Forest, Decision Tree, Naive Bayes, Backpropagation NN, XGBoost, AdaBoost, and Ensemble RF-BPNN.• Security orchestrator This part of closed-loop automation enforces the AI reaction agent's security prac- tices.It enforces IoT security regulations utilizing SDN and NFV with the control and management block.The security orchestrator instantiates, configures, and monitors virtual security devices, manipulates bad traffic through SDN, or directly controls IoT machines, like shutting off a hacked device.
We have addressed the IoT security threats using RF, NB, DT, NNs, XGBoost, AdaBoost, and Ensemble RF-BPNN, which involve leveraging ML algorithms to detect and mitigate potential risks.To highlight their effectiveness, we can compare some of these approaches to traditional security methods as follows: 1. RFs are an ensemble learning algorithm that combines multiple DTs to enhance accuracy and robustness.
They applied to the proposed IoT security system as follows: a. Ensemble construction RF consists of multiple DTs, each trained on a randomly selected subset of the training dataset.This randomness helps to reduce overfitting and increase generalization.b.Classification When classifying new instances, each DT in the RF independently predicts the class.The last prediction depends on the majority vote or averaging of the individual tree predictions.
2. Decision trees (DTs) are a popular ML technique for classification and regression tasks.The proposed IoT security system uses a DT classifier to identify and address unique threats, and it works as follows: a. Feature selection The first stage is to select relevant features from the IoT device data.These features can include network traffic patterns, device behavior, communication protocols, and more.b.Training Using a labeled dataset, we train a DT classifier that contains instances of both normal and malicious behavior.The model learns to classify instances based on the selected features.c.Detection Once trained, the DT can classify new instances as normal or malicious, depending on their feature values.If the DT classified an instance as malicious, it would take appropriate security measures, such as blocking network access or raising an alarm.
3. Neural networks NNs, particularly DL architectures, have gained significant popularity in various domains, including IoT security.Here's how they can be used: a. Multiple layers of interconnected nodes (neurons) form the architecture design of a neural network model.Each neuron applies a non-linear activation function to weighted inputs from the previous layer.b.We train the neural network using a labeled dataset through a process known as backpropagation.To reduce the discrepancy between the expected and observed labels, we iteratively tweak the network's biases and weights.c.Prediction: Once trained, the neural network can classify new instances into different threat categories based on their input features.
• Comparative analysis with traditional approaches Compared to traditional security approaches, such as rule- based systems or signature-based detection, ML techniques offer several advantages.Traditional methods rely on predefined rules or patterns, which might not be able to adapt to rapidly evolving threats.In contrast, ML methods can learn from data and adapt their behavior accordingly.They can detect anomalies, identify new attack patterns, and improve over time as they encounter new threats.However, traditional approaches often provide better interpretability and explainability.
Rule-based systems explicitly define security rules, making it easier for security analysts to understand and verify their behavior.However, ML models, especially complicated ones like neural networks, are black boxes, making their decision-making process difficult to comprehend.
In conclusion, ML techniques like DTs, RFs, XGBoost, AdaBoost, and neural networks provide powerful tools for addressing unique IoT security threats.They offer improved accuracy, adaptability, and the ability to handle complex and evolving attack patterns.However, they may trade off some interpretability compared to traditional security approaches.The approach is selected based on the specific requirements of the IoT security system and the trade-offs between accuracy, interpretability, and computational requirements.

Performance evaluation of the proposed model
The experimental methodology and analysis outcomes of the AI-based response agent are covered in this section.An AI-based response agent can identify potential threats by performing the following steps: (1) Evaluate network patterns.To identify various forms of network infiltration, the research presents a knowledge-based intrusion detection framework.(2) Examine the strange behaviors that have been seen in the IoT system.Here, attacks are uncovered through the investigation of strange actions taken by IoT devices.To appropriately categorize the degree of the attacks and select the right security solutions, the research has applied supervised learning algorithms.The AI-based reaction agent will employ many ML approaches, considering the appropriate inputs from the monitoring agents, to remove a specific attack.
• Evaluating network patterns Intrusion system evaluation is the first stage in evaluating the framework's effec- tiveness.
Several publicly available datasets, including the UNSW_NB15, IoT-23, DARPA, KDD 99, NSL-KDD, DEF-CON, and balanced BoTNeT-IoT-L01 datasets, were used to build the proposed system (see the datasets link (https:// drive.google.com/ drive/ folde rs/ 1gjP-pQzFZ sLh2Q MsIa5 GPhEh 5etv9 Jvc? usp= shari ng)).These datasets contain information on IoT attacks in the form of (.csv) files.Table 1 shows the network traffic information from different IoT devices.Advantages of the NSL-KDD dataset compared with the initial KDD dataset: The train set does not contain duplicated data; therefore, classifiers are not biased toward more frequent records.BoTNeT-IoT-L01 is a recent dataset that consists of two Botnet assaults (Gafgyt and Mirai).Over a 10-s frame with a decay factor of (0.1), the mean, count, variance, radius, magnitude, correlation coefficient, and covariance were the seven statistical measures that were computed.The .csv file was used to extract four features: jitter, packet count, outbound packet size alone, and combined outbound and inbound packet size 37 .By computing three or more statistical measures for each of the four traits, a total of twenty-three features were obtained.
Furthermore, this study used the widely recognized NSL-KDD dataset as a benchmark.It served as a benchmark for assessing intrusion detection systems in this research.It is a much better version of dataset KDD 99 (see Table 2).The NSL-KDD dataset has over 21 distinct attack types, which serve as the foundation for the application of our proposed IDS model, such as teardrop, satan, rootkit, buffer-overflow, smurf DDoS, pod-dos, and Neptune-dos.The NSL-KDD dataset is primarily composed of preprocessed network traffic data.These data provide a more precise representation of the network traffic that occurs at present.There are two distinct collections of data inside the dataset: a set for testing and a set for training.Comparatively, the set of testing has around 23,000 records, whereas the training set contains approximately 125,000 records.Each entry in the dataset corresponds to a network connection and contains a set of 41 features, including the IP addresses of the source and destination, protocols, flags, and a label indicating whether the connection is normal or abnormal (anomalous).Each sample in the dataset corresponds to certain attacks as follows: DoS attacks, remote-to-local (R2L) attacks, user-to-root (U2R) attacks, and probing attacks 38 .There are many implementation tools available for analyzing IoT attack datasets, such as Wireshark, Snort, Zeek (formerly Bro), Jupyter Notebook, Python, and Weka.In this work, the researchers used Python programming and Weka data mining tools for ML and data analysis processing.
The proposed tools include a large collection of ML algorithms for classification, regression, clustering, and association rule mining, such as RF, NB, DT, NNs, XGBoost, AdaBoost, and Ensemble RF-BPNN, as well as tools for model evaluation and selection, including cross-validation and ROC analysis.
Certain ML algorithms are incapable of learning due to the wide range of features present in nature.The modeling process becomes more challenging when a feature is continuous.Hence, before constructing classification patterns, preprocessing is fundamental to optimize prediction accuracy.Specifically, a discretization technique is used to overcome this restriction.When applied to a continuous variable, the discretization data mining approach seeks to minimize the number of possible values by categorizing them into intervals.Two different kinds of discretization are discussed in the literature: (1) static variable discretization, in which variables are partitioned separately, and (2) dynamic variable discretization, in which all features are discretized concurrently 39 .The research discretized the attacks and then categorized them such that the research was left with only the most common types (UDP, Junk, Ack, and UDP plain from the balanced BoTNet-IoT-L01 dataset and DDoS, Probe, U2R, and R2L from NSL-KDD).

Metrics for comparing performance Choosing measures that can indicate the strength of an IDS is a major
problem when evaluating an IDS.An IDS's performance goes well beyond its classification results alone.Cost Per Example (CPE), precision, detection rate, and model accuracy are utilized to evaluate the effectiveness of the proposed system.When evaluating outcomes, the following metrics should be used in conjunction with one another 40 .
Equation (1) indicates Cost-Sensitive Classification (CSC) or CPE, where N is the total number of samples, CM refers to the classification's Confusion Matrix algorithm, and C is the Cost Matrix (see Table 3) 41 .

Input data cleaning, feature extraction, and classification
The research proposes a first method, which involves preparing the entire dataset and then categorizing it using a variety of techniques (Hoeffding Tree, RF, Bayes Net, and J48) as shown in Fig. 6.Next, the research chooses the best classifier (algorithm) that generates a preferred accuracy (see Table 4 for the BoTNet-IoT-L01 dataset and Table 5 for the NSL-KDD dataset). ( CM i, j + C i, j .Normal.An extra hidden layer was incorporated to facilitate the learning process.This method uses 100 neurons and a single hidden layer.Experience has shown that the alternative hidden layer and neuron counts did not increase the mean squared error (MSE) (see Table 6).4. Distributed classification module This module introduces a distributed categorization system in which the various types of attacks (DDoS, U2R, R2L, and Probe; UDP, UDP plain, Ack, and Junk) are all assigned to the Ensembled RF-BPNN algorithm.Finally, the AdaBoost method is used to combine the resulting models (see Table 7).

Result evaluation and discussion
The findings reported in Table 5 demonstrate both the accuracy rate and precision of the RF technique.Unfortunately, the results are not promising for either U2R or U2L attacks.There is a low misclassification rate (or CPE) and high accuracy when using J48 to identify attacks.When it comes to the accuracy required for U2R strikes, however, J48 falls short.Despite its consistent performance, the Hoeffding tree method has a low accuracy for U2R threats.Although it has a strong model accuracy, the Bayes Net method provides the lowest results, failing to identify the vast majority of U2R threats.As can be seen from Table 6, the backpropagation process is generally as precise as its predecessors, if not somewhat more so.However, misclassification comes with a significant processing time penalty.AdaBoost, CPE, and detection rate produced a better detection accuracy model as shown in Table 7.A classification algorithm for IoT detection based on ensembles of backpropagation neural networks is trained on the BoTNet-IoT-L01 dataset (see Table 8).The novelty of the algorithm stems from the methodology employed for combining outputs of the backpropagation neural network ensembles.The backpropagation neural network Oracle 8i database tool is utilized to combine the ensemble outputs.As Fig. 5 shows, the neural network backpropagation Oracle is constructed with an RF algorithm that produces high classification accuracy and low classification error (see Table 4).The thresholds are not learned all at once in the RF model but rather hierarchically.The decrease in impurity will be enforced one directionally from the starting to the finishing index of the symbolic path; however, the research learned them simultaneously.The idea of hierarchical node splits will be represented by this one-directional impurity reduction.To do this, firstly, the research breaks up each node in the symbolic path into some votes for each class.Secondly, the research computes the impurity based on those votes.The third step is to gradually lower it by a certain amount using the Softmax activation method.Our proposed algorithm uses margin ranking loss as its objective function.It is important to maintain a minimum margin    disparity between the intended result and the actual one.The margin difference is the 'reduction in impurity' .
The target is output shifted by one index to the right and the impurity at first split is initialized by the impurity of the batch (see Fig. 5).
When employing the AdaBoost classifier as a detection model, the research was limited to considering a single window size.Therefore, the research has successfully decreased the number of attributes in the BoTNeT-IoT-L01 dataset from 115 to 23.This significant decrease in the dimensionality of the dataset results in a significant acceleration of the detection process.Speaking of the BotNet-IoT dataset, the research discovered that just a small number of parameters have an important role in our system's overall performance, and time windows of 10 s performed marginally better than those of shorter duration (see Fig. 6).Additionally, the research discovered that traffic heterogeneity greatly impacted RF classifier performance.However, when compared to the other classification algorithms, AdaBoost and RF-BPNN had the greatest and most stable results (see Table 7).
Figure 7 shows the accuracy for detecting DoS, Fuzzers, Generic, Backdoor, and Exploit attacks in the UNSW_ NB15 dataset using the RF classifier and SMOTE (where "label" refers to the target variable and "attack_cat" refers to the attack types).
Different experiments determine the system's performance.Examining and validating each stage using the supplied classifiers is necessary to confirm the experimental results.Whether the classifier can discriminate across feature categories is also crucial.Accuracy, specificity, precision, recall, F1-score, and AUC measure the model's performance and indicate the correctness of the system.Such measurements are based on the T P , F P , T N , and F N , as shown in Eqs. ( 2) to (6):  Thus, the accuracy formula evaluates the classifier's capacity to accurately categorize both positive and negative instances; precision denotes the classifier's ability to avoid incorrectly labeling positive instances as negative, and specificity denotes its capacity to avoid incorrectly labeling negative instances as positive.In machine learning, recall is the rate at which a classifier can identify positive examples, whereas the F1-score is the weighted average of accuracy and recall.
Table 9 shows the performance of seven machine learning classifiers using the Synthetic Minority Oversampling Technique (SMOTE) on the UNSW_NB15 dataset.As you can see in Fig. 8, the RF, XGBoost, AdaBoost, and Ensembled RF-BPNN classifiers did the best overall.They achieved an accuracy of 99.9%, an AUC of 1, and an F1 score of 99.9%.The Naive Bayes classifier, on the other hand, obtained the minimum accuracy and F1 score.
(2) Accuracy = T P + T N T N + T P + F N + F P ,

Figure 3
Figure 3 illustrates the proposed ML-based security model to address IoT security issues based on NFV, SDN, and ML technologies.The figure displays the security component framework and interconnections, whereas Fig.4demonstrates the closed-loop automation phases, starting with detection and monitoring and ending with preventing threats.To ensure complete security, the system suggested integrating the enablers and countermeasures from the previous subsections.This framework enforces security policies beginning with the design and concluding with the application and maintenance.Two primary framework levels are shown in Fig.3(i.e., security orchestration and security enforcement layers).The two layers and their closed-loop automation intercommunications to detect and prevent attacks are discussed below.

Figure 3 .
Figure 3.The proposed ML-based security model.

Figure 4 .
Figure 4. Automation with a closed loop, from detection to prevention.

Figure 6 .
Figure 6.RF-BPNN accuracy evaluation for each attack type in the balanced BoTNet-IoT-L01 dataset.

Figure 7 .
Figure 7.The accuracy for detecting some attacks in the UNSW_NB15 dataset, using RF Classifier.
• Adaptive IoT systems Reinforcement learning can be used to optimize IoT system parameters or con- figurations based on real-time feedback and changing conditions.•Smart resource allocation ML models can learn to allocate resources dynamically based on demand, user preferences, or changing network conditions.
4. Deep learning DL algorithms, especially deep neural networks, excel at processing complex data and extracting high-level features.In IoT, DL has various applications, including: • Image and video analysis DL models can analyze images or video streams from IoT devices, enabling applications like object detection, surveillance, or facial recognition.• Natural language processing (NLP) DL techniques can process and understand text or voice data from IoT devices, enabling voice assistants, sentiment analysis, or chatbots.• Time-series analysis DL models, such as long short-term memory (LSTM) or recurrent neural networks (RNNs) networks, can analyze time-series sensor datasets for predicting future values or detecting anomalies.
SDN is a cutting-edge networking model that separates the data plane from the control plane.This improves network programmability, adaptability, and management, and it also enables external applications to control how the network behaves.The SDN's three basic components are communication interfaces, controllers, and switches.Cognitive judgments were imposed on the switches by a central authority (i.e., the SDN controller).It keeps the state of the system up to date by changing the flow rules of the appropriate switches.IoT systems' success and viability depend on SDN adoption.To handle IoT networks' huge data flows and minimize bottlenecks, SDN's routing traffic intelligence and improving usage of the network are essential.This connection may be applied at many layers in the IoT network, including enabling end-to-end IoT traffic control, core, access, and cloud networks (where creation, processing, and providing of data takes place).SDN also enhances IoT security, for example, tenant traffic isolation, tracking centralized security based on the network's global view, and dropping of traffic at the edge of the network to ward off malignant traffic.• Network function virtualization (NFV) Virtualization in network contexts is called network function virtual- ization (NFV).NFV separates software from hardware, adding value and reducing capital and operational costs.The European Telecommunications Standards Institute (ETSI) has standardized this approach's novel design for use in telecommunications systems.The architecture of ETSI NFV has three basic components: (a) Virtualization infrastructure Virtualization technologies are found in this layer in addition to needed hardware that offers abstractions to resources for Virtualized Network Functions (VNFs).Cloud platforms handle networking, data processing, and storage.(b) Virtual network functions VNFs replace specific hardware equipment for network functions.They scale and cost-effectively handle network services across numerous settings.(c) Management and orchestration Block of Management and orchestration (MANO) is a component of ETSI NFV and is responsible for communicating with the VNF layer and the infrastructure layer.It manages monitoring VNFs, configuration, instantiation, and global resource allocation.

Table 2 .
Public used datasets for IoT detection system.Backpropagation approach To investigate the multilayer neural net approach, the research utilized the capabilities of a backpropagation technique for learning.The research employed a multilayer neural network with three layers.The initial layer had 41 inputs, representing the features of the dataset.The final layer encompassed the classification responses, namely, U2L, U2R, Probe, DoS, and

Table 3 .
The cost matrix for analyzing the NSL-KDD dataset.

Table 4 .
Performance assessment of different ML methods with a balanced BoTNet-IoT-L01 dataset.

Table 5 .
The precision rate of used ML algorithms for each attack from NSL-KDD.

Table 7 .
The evaluation metrics of the AdaBoost technique.

Table 9 .
Performance metrics for 7 ML algorithms using the UNSW-NB15 dataset and SMOTE.

with existing IoT security frameworks and standards
The proposed model can integrate with existing IoT security frameworks and standards as follows:1.Integration with IoT security frameworks The ML-based model can integrate with IoT security frameworks by aligning its functionalities with their security objectives and guidelines.For example:a.The proposed model can integrate with existing authentication mechanisms recommended by IoT security frameworks, such as digital certificates or secure bootstrapping protocols.It can enhance device authentication by analyzing device behavior patterns and detecting anomalies that may indicate unauthorized access or compromised devices.b.To align with data privacy requirements, the model can utilize encryption techniques and privacypreserving algorithms recommended by the IoT security frameworks.It provides a guarantee of secure transmission and storage of data, protecting confidential information against illegal access.c.The proposed model can integrate with existing access control mechanisms defined by IoT security frameworks.It can augment access control by providing intelligent decision-making capabilities based on historical data, user behavior analysis, or contextual information.This aids in assessing access requests and preventing unauthorized access to IoT resources.2. Integration with IoT security standards The ML-based model can comply with IoT security standards by incorporating the required security controls and practices.For example: a.The proposed model can align with ISO/IEC 27000 standards by implementing appropriate security controls for risk assessment, incident management, and data protection.It can follow the standards' guidelines to ensure that the necessary security measures are in place.b.The model can follow the NIST framework to enhance its threat detection and incident response capabilities.3. Interoperability in IoT ecosystems By adhering to standard IoT protocols, data formats, and metadata standards, the ML-based model can ensure interoperability.For example: a.The ML model can communicate with IoT devices and gateways using standard IoT protocols such as MQTT or CoAP, ensuring compatibility and interoperability across different devices and platforms.b.The ML model can use commonly used data formats, such as JSON, or semantic data models, such as the Semantic Sensor Network (SSN) ontology, to facilitate seamless data sharing and interoperability with other components within the IoT ecosystem.

Table 10 .
Comparing the results with earlier studies.

Table 11 .
Time complexity of training and testing for the ML algorithms used.